A model for friction in quasi-steady-state sliding. II, Numerical results and discussion

Numerical results and comparisons with some experimental data for a newly developed theoretical model for the prediction of the coefficient of friction for elasto-plastic surfaces in quasi-steady-state sliding is presented. A companion paper presents the derivation of the model, which considers the separate effects of asperity interaction and deformation, debris interaction and plowing, and adhesion, with partitioning of normal load (and contact areas) between different contacting elements. Here the significance of various parameters which appear in the model is reviewed and suggested values are determined for use in cases where not all quantities are known. It is seen that mechanical properties, surface roughness characteristics and the size and quantity of entrapped debris are important factors, while adhesion is not. Finally, by comparing theoretical results with some experimental data from the literature, the overall predictive capability of the model is shown to be quite good. The materials examined were steel, Cu, and Cr.